feat: lunch reminder + recap email templates

Adds sendLunchReminderEmail and sendLunchRecapEmail. Templates use
Intl.DateTimeFormat with Europe/Monaco zone. Reuses existing
escapeHtml helper.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

tests/unit/lunch-upsert-pick.test.ts

@@ -8,6 +8,7 @@ import {
   uid,
 } from '../helpers'
 import { lunchRouter } from '@/server/routers/lunch'
+import type { UserRole } from '@prisma/client'
 
 const programIds: string[] = []
 const userIds: string[] = []
@@ -77,7 +78,7 @@ async function setupTeam(opts: {
   return { program, lead, member, admin, project, attendingMember: am, dish, event }
 }
 
-function callerFor(user: { id: string; email: string; role: string }) {
+function callerFor(user: { id: string; email: string; role: UserRole }) {
   return createCaller(lunchRouter, user)
 }